It's usually due to avoid choking hazard (reason why Mc'toran and Galidor polybag have large piece chunk) and Lego will not likely do that again since specialized molded piece tend to cost alot nowaday.

I recognize those! They're pins for retail store employees during product launch events. I have one from a 2001 BIONICLE Launch Event package that I procured from another AFOL a couple years back. These event kits were originally sent out to various retailers and contained lots those badges, a Kanohi mask grab box and some pretty nifty cardboard cut-outs like this one:

it strange that the jetrax show as the limited edition one instead of the normal one

Maybe it was designed first?

kanohippy:

a deteriorating Ignika?

It's a piece of '08 promo art that I've personally seen before (though I can't put my finger on exactly where though). It's viewable in the BioMediaProject's archive.

Square:

Lego will not likely do that again since specialized molded piece tend to cost alot nowaday

LEGO isn't against producing highly specialized moulds for their limited-run Collectible Minifigures series. I think that the problem lies with the choking hazard standards Happy Meal toys have to adhere to (I imagine they've gotten more strict in the 15+ years since the McToran).

Yeah, it's on the tops of the Mistika canisters (with the Toa's having the sleek portion on the front and the Makuta having the deteriorating one on the front) and on the background of the Phantoka posters.